Over at Spacing, journalist John Lorinchas just published part four in an epic, five-part investigation into why, exactly, the city and the province got together last year to overturn years of transit planning in Scarborough. The now-infamous policy reversal resulted in the breaking of a signed, sealed agreement to replace the Scarborough RT with a seven-stop light-rail line. Instead, for reasons that Lorinc’s investigation makes significantly clearer, former TTC chair (and current mayoral candidate) Karen Stintz and provincial transportation minister Glen Murray teamed up to scrap the light-rail plan in favour of a three-stop subway that will cost significantly more to build.

Here, five things we learned from Lorinc’s piece, the first part of which is here.

1. The two councillors most responsible for scrapping the light-rail line had very specific motives

Politics-watchers have always supposed that the push for a Scarborough subway extension was politically motivated, but Lorinc provides a more detailed analysis. Karen Stintz, he writes, thought the subway would bolster her eventual mayoral bid. The subway’s other early proponent, Scarborough councillor Glenn De Baeremaeker, may have been trying to counteract the effect of critical robocalls to his constituents, courtesy of Rob and Doug Ford.

2. The province got involved early

From the public’s perspective, it often seemed as though the Liberal provincial government was merely bending with city council’s changing political winds, but Lorinc has found evidence that Kathleen Wynne’s cabinet was actively involved in bringing the Scarborough subway extension up for discussion. According to Lorinc, Stintz met with provincial transportation minister Glen Murray in April 2013, and after that Murray became involved in an elaborate, multi-month effort to advance the subway scheme while making Queen’s Park seem like a passive participant. The subway push conveniently came to a head during a provincial by-election in Scarborough-Guildwood, which the Liberals ultimately won.

3. We may be drastically underestimating the cost of building the subway

The cost of building the Scarborough subway extension has been estimated at around $3 billion, but Lorinc finds reason to believe that the real cost would be higher. A business-case analysis he obtained from Metrolinx says it’s too early in the planning process to predict the financial burden accurately. In other words, the city and the province approved a plan on which their own experts couldn’t fix a price tag. (The light-rail proposal was estimated at around $1.8 billion.)

4. The subway’s ridership projections are dismal

Lorinc found documents in which Metrolinx staff warn politicians about the subway’s fatal flaw: even in 2031, after years in operation, it would only carry about 11,000 passengers per direction per hour at peak times, which is less than half a subway line’s capacity. (Light rail can carry around 15,000 passengers per direction.) “Preliminary analysis indicates that the subway scheme will not represent a good use of public investment dollars,” said one memo.

5. And there may be other hidden costs we don’t know about yet

Cancelling the Scarborough light-rail line eliminated the need for 48 light-rail vehicles that had already been ordered from Bombardier. Lorinc says nobody—not even Metrolinx—is entirely sure how much it will cost to renegotiate that contract.